Wikipedia is a free, web-based, collaborative, multilingual encyclopedia project supported by the non-profit Wikimedia Foundation. Its 20 million articles (over 3.82 million in English alone) have been written collaboratively by volunteers around the world. Almost all of its articles can be edited by anyone with access to the site, and it has about 100,000 regularly active contributors. As of July 2011, there are editions of Wikipedia in 282 languages. It has become the largest and most popular general reference work on the Internet.
Wikimedia Foundation, Inc. is an American non-profit charitable organization headquartered in San Francisco, California, United States, and organized under the laws of the state of Florida, where it was initially based.
The Wikimedia Foundation's stated goal is to develop and maintain open content, wiki-based projects and to provide the full contents of those projects to the public free of charge.